Foster Propell Compounds Improve Catheter Manufacturing

Foster Corporation has introduced ProPell thermoplastic polyurethane (TPU) and polyether block amide (PEBA) compounds for improved manufacturing and handling of medical catheters. These new compounds dramatically reduce tackiness and friction in soft, flexible polymers while maintaining other physical properties of the unmodified polymers.

Soft grades of TPU and PEBA polymers, with hardness properties ranging from 80 Shore A to 35 Shore D, are commonly used in medical catheters that require flexibility to navigate vascular pathways without causing trauma. Yet, the inherent high friction and tackiness of these polymers causes handling problems during catheter tube extrusion and packaging since the parts stick to each other. Catheters made from these materials can also be difficult for physicians to handle and push through vascular pathways.

ProPell low friction compounds use a proprietary, non-migratory additive that enhances the surface of parts without substantially altering the physical properties of the polymer. Tests show that parts produced from ProPell TPU have a dry coefficient of friction of 0.05, representing a 66% reduction compared to the unmodified TPU polymer with a hardness of 80 Shore A. The results are even more pronounced in PEBA polymers with a hardness of 35 Shore D. Parts made from ProPell PEBA have dry coefficient of frictions 84% lower than the unmodified polymer, while maintaining similar tensile strength and elongation properties.

“Catheter manufacturing engineers have put up with the tackiness inherent in many soft polymers because they are otherwise great for flexible, traumatic components,” said Amar Nilajkar, application development manager for Foster Corporation. “ProPell compounds were designed to maintain all the great physical properties of these materials while providing a smoother, lower friction surface in medical device components.”